The present invention relates to a magnetic recording medium, in particular to a magnetic recording medium having an improved backing layer which is coated onto a side of a support opposite to a magnetic layer which is coated to the support.
In general, the magnetic recording medium such as magnetic tape for a video tape recorder comprises a support, a magnetic layer (or a magnetic recording layer) and a backing layer on the opposite sides of the support, forming a thin tape so as to enable high density recording.
Conventional magnetic thin tapes having a smooth finished surface to provide improved electromagnetic properties such as signal-to-noise ratio cannot be uniformly and orderly wound or rewound, so that tension variations during such winding or rewinding reduce its running properties and cause unstable output. In addition, the tape may be easily distorted or damaged.
In order to overcome the aforementioned defects, a surface of the backing layer has been roughened with minute concaves and convexes so as to provide better running properties and running durability. However, these magnetic recording media having such an improved backing layer, particularly in the case of magnetic tape, have such a defect that the concaves and convexes of the backing layer are transferred to the surface of the surface of the adjacent magnetic layer when the magnetic recording medium is taken up in roll or stacked in sheet, thereby impairing electromagnetic properties, in particular decreased signal-to-noise ratio. In other words, it is difficult for conventional magnetic recording media to fulfill both the requirements of electromagnetic properties and running properties simultaneously.
For example, wear, increase in coefficient of friction, and breaking of tape tend to occur in the backing layer of the conventional magnetic recording medium. Also the conventional magnetic recording medium is easily electrostatically charged due to high surface resistivity, which causes depositing of dusts and flake-offs onto the magnetic recording medium and the consequent frequent dropoff.